Projectile throwing or launching apparatus

ABSTRACT

A sports ball throwing apparatus is disclosed which may be used to propel projectiles including footballs, softballs soccer balls and model rockets and airplanes. The apparatus has a barrel the azimuth and elevation of which are adjustable for launching a projectile in different directions. A projectile having a cavity is mounted on the end of the barrel to be launched using air pressure stored in the apparatus. Safety is provided in that compressed air is not available until a projectile having a cavity is mounted on the end of the barrel and a switch closes a circuit to activate an air compressor. The switch may be placed at either end of barrel so long as it is operated when the projectile is fully mounted on the barrel. In addition, a seal inside the base of the projectile is used to seal the barrel so that compressed air is not available until the projectile is fully mounted on the barrel. Spiral flight of the projectile is provided by helical grooves on the outside of the barrel that engage protrusions on the inside of the projectile cavity when the projectile is mounted on the barrel for launching. When the projectile is launched the protrusions ride along the helical grooves and impart a spiral spin to the projectile. To assist in the spiral spin of the projectile there are straight grooves on the surface of the projectile and at an angle to the longitudinal axis of the projectile. Air passing over the moving projectile interacts with the grooves on its surface to maintain the spiral spin of the projectile.

CROSS REFERENCE TO RELATED APPLICATION

This utility patent application claims rights under 35 U.S.C. 119(e) from U.S. provisional patent application No. 60/512,813 entitled “Sports Ball Throwing Machine”, and filed Oct. 18, 2003.

FIELD OF THE INVENTION

This invention relates to projectile throwing or launching apparatus and more particularly to apparatus that throws or launches a model rocket or sports ball.

BACKGROUND OF THE INVENTION

In the prior art there are numerous apparatus that are used for passing, throwing or launching footballs, sports balls and other projectiles such as model rockets. Such throwing apparatus can emulate spiral flight form. One version of such an apparatus is disclosed in U.S. Pat. No. 4,026,261 which describes an apparatus that employs two spaced, rotatably-driven, pneumatic-tired wheels that have their outer surfaces confronting each other and spaced apart a distance less than the maximum diameter of a football to be thrown. The wheels are mounted in such a way that the planes in which they rotate can be independently varied. In this manner, the direction and rate of spin of a spiral pass can be set. Alternatively, the wheels can be positioned to rotate in the same plane as is often done to attain end-over-end flight.

Another apparatus for passing footballs is disclosed in U.S. Pat. No. 4,723,532 which also utilizes spaced apart confronting surfaces of spinning wheels.

These prior art football passing apparatus are complex and expensive and meant mainly for use in professional football.

Yet another apparatus used for passing footballs is disclosed in U.S. Pat. No. 4,291,663. This football passing apparatus utilizes a spring that is located in a cylindrical, hollow tube. The spring is first extended and is then released to provide the force to propel a football. One end of the spring is connected to an upper end of the tube, and the other end of the spring is loose but connected to a platform that is mounted on and rides alongside the outside of the tube. To connect the platform to the spring internal to the tube there is an elongated narrow aperture though the wall of the hollow tube that extends in a helical fashion along a portion of the tube. The spring and platform are connected through this aperture. When the spring is extended the platform connected thereto is at the bottom of the helical, elongated aperture. A football having a coaxial cylindrical channel through its length is placed down over the exterior of the hollow tube to sit on the platform. When the stretched spring is released the platform travels up the tube in a spiral fashion along the helical aperture. The football sitting on top of the platform is thereby launched with a spiral spin. The one drawback to this football passing apparatus is that to throw a pass of twenty yards or so requires a spring that is so strong that it cannot practically be used by children.

SUMMARY OF THE INVENTION

The projectile throwing apparatus disclosed herein is only described with reference to a football because it is desirable to provide spin to a football. However, the apparatus may be used with other sports balls, such as a soccer ball or a model rocket where a spiral spin may not be needed.

The novel apparatus described and claimed herein uses an air compressor and store compressed air is used to launch a projectile such as a sports ball or model rocket. By adjusting the level of air pressure of the stored compressed air until a ball or rocket is thrown or launched, a projectile may be thrown or projected a short distance or a relatively long distance.

The projectile passing apparatus has a chamber and a barrel in which the compressed air is stored until utilized to launch a projectile such as a football. The projectile has a cavity in its rear end that is placed over a launching end of the barrel. The barrel is pointed in a direction and at an elevation at which it is desired to launch the projectile. When the compressed air is released the projectile on the end of the barrel is launched from the barrel in the chosen direction and elevation.

To prevent any items, other than the projectile provided with the throwing apparatus from being placed on the end of the barrel and being launched, a safety switch is provided. The safety switch only permits the air compressor to be energized to produce compressed air when the provided projectile is placed on the launching end of the barrel. The switch provides a first level of safety against misuse of the throwing apparatus.

A second level of safety is provided against misuse of the projectile throwing apparatus. When the provided projectile is not positioned on the launching end of the barrel, the chamber and barrel of the apparatus are not sealed and air pressure cannot build up therein to launch anything even if the air compressor is activated. Inside the cavity in the rear of the projectile is a sealing element that seals the end of the barrel to permit air pressure to build up in the barrel and chamber only when the projectile is fully mounted on the launching end of the barrel. Thus, the safety switch may not be operated to activate the air compressor and build up air pressure.

To launch a projectile on the launching end of the barrel a manually adjustable release mechanism is provided. When the compressed air reaches a certain pressure level as determined by the release mechanism, the projectile is released and is launched. With higher air pressure the further the projectile will be thrown and visa versa.

When it is desired to impart a spin to a projectile, such as a football, during launch other elements are utilized. On the outside wall of the barrel are helical, rifling grooves. These grooves start at the launching end of the barrel and go back along the barrel. Inside the cavity in the rear of the projectile are protrusions. A protrusion sits in each of the grooves when the ball is placed on the end of the barrel to be launched. When the projectile is launched the protrusions ride along the grooves as the projectile leaves the barrel thereby imparting a spiral spin to the projectile. Such a spiral spin is desirable for a football.

The projectile has a number of straight, parallel grooves in its outer surface that are not helical but are at an angle with respect to the longitudinal axis of the projectile. These grooves help maintain the spiral spin of the projectile after it is launched from the throwing apparatus. As the projectile travels through the air the air moving over the projectile interacts with the side walls of the grooves to maintain the spin of the projectile.

DESCRIPTION OF THE DRAWINGS

The invention is best understood upon reading the following Detailed Description in conjunction with the drawing in which:

FIG. 1 is a side view of the novel projectile throwing apparatus;

FIG. 2 is a side view of a projectile in the form of a grooved football;

FIG. 3 is a rear perspective view of a projectile in the form of a football showing a cavity in the rear end of the ball;

FIG. 4 is a side cutaway view of the cavity in a projectile and the launching end of the barrel when the projectile is not yet mounted on the end of the barrel of a first embodiment of the invention;

FIG. 5 is a side cutaway view of the launching end of the barrel with a projectile in mounted thereon for launching for the first embodiment of the invention;

FIG. 6 is a side cutaway view of the launching end of the barrel with the projectile mounted thereon for launching when an element inside the launching end of the barrel is retracted to release stored compressed air and launch the projectile for the first embodiment of the invention;

FIG. 7 is a side cutaway view of a spring loaded, manually adjustable air piston at the rear of the throwing apparatus used to adjust the air pressure for launching the projectile for the first embodiment of the invention;

FIG. 8 is a block schematic diagram of the circuitry used to power the throwing apparatus and showing a safety switch used to energize the compressor only when a projectile is mounted on the end of the barrel for the first and a second embodiment of the invention.

FIG. 9 is a side cutaway view of a second embodiment of the invention showing the launching end of a barrel with a projectile being slid thereon;

FIG. 10 is a side cutaway view of the second embodiment of the invention showing the launching end of a barrel with a projectile fully mounted thereon and ready for launching; and

FIG. 11 is a side cutaway view of a portion of the second embodiment of the invention showing a pressure sensing and projectile releasing mechanism.

DETAILED DESCRIPTION

The projectile throwing or launching apparatus disclosed herein is only described with reference to a football because it is desirable to provide spin to a football. However, the apparatus may be used with other sports balls, such as a soccer ball or softball, or with a model rocket, where spin may not be needed. The apparatus uses an air compressor to create compressed air that is stored and used to launch the sports ball or other projectile. By adjusting the pressure of the compressed air a projectile may be launched a short distance or a relatively long distance.

In FIG. 1 is shown a side view of the novel sports ball throwing apparatus 10 of a first embodiment of the invention. The major individual elements of apparatus 10 are introduced with reference to FIG. 1 and those elements are explained in more detail with reference to FIGS. 4 through 6. Starting at the left or launching end 16 of apparatus 10, there is a barrel 12 that is connected to an air chamber 11. When barrel 12 is sealed, compressed air may be stored in the barrel and in the chamber for launching a football 19, not shown in this figure but shown in and described with reference to FIGS. 2 and 3, off launching end 16 of barrel 12. At the rear of air chamber 11 is a piston chamber 37 in which is a piston 41 that is not shown in FIG. 1 but which is shown in and described in detail with reference to FIG. 7. At the rear of piston chamber 37 is an air pressure adjustment knob 38 that is manually adjustable to adjust the air pressure that will build up in barrel 12 and chamber 11 before a football 19 is launched. Passing through the entire length of the apparatus just described is a rod 18. Rod 18 is connected to an element 27 just inside end 16 of barrel 12. Rod 18 extends through barrel 12 and chamber 11 into piston chamber 37 where it is connected to a piston 41, not shown in this Figure but shown in FIG. 7, and then continues to exit chamber 37 through adjustment knob 38. Rod 18 functions to transfer the motion of piston 41 to an element 27 just inside end 16 of barrel 12 to launch the football 19 as described in greater detail further in this detailed description.

There is a pair of individual insulated conductors 17 a and 17 b making up a wire cable 17 that goes to end 16 of barrel 12 to a football safety switch. The football safety switch provides a first level of safety against misuse of apparatus 10 in that only the ball provided with apparatus may be launched therefrom because only it can operate the football safety switch. The safety switch is shown in and described in greater detail with reference to FIGS. 4 through 6. Cable 17 passes through barrel 12 and chamber 11 where it exits the chamber at an air tight exit 54 to be connected to other circuitry of apparatus 10. The circuitry is shown in and described with greater detail with reference to FIG. 8.

There is as a main body 52 of the apparatus 10 in which is detachably mounted a rechargeable battery 13 that provides electrical power for running the apparatus. Battery 13 may be released using a latch 12. There is also a main power on-off switch 14 that is used to turn apparatus 10 on and off. Mounted through the wall of main body 52 is an air compressor 47 that is used to provide compressed air to launch a football from apparatus 10.

A second level of safety is provided against misuse of the throwing apparatus 10. When the provided football (not shown) is not positioned on the open end 16 of barrel 12, chamber 11 and barrel 12 are not sealed in order to build up air pressure if compressor 47 is activated without the use of the football safety switch that is activated by the presence of the football on launching end 16 of barrel 12. This is shown in and described in greater detail with reference to FIGS. 2 through 4.

FIG. 2 shows a side cutaway view of cavity 21 in the rear of football 19 and the launching end 16 of barrel 12 just before football 19 is mounted on the end of barrel 12. Inside cavity 21 of football 19 is fastened a plastic, cylindrical sleeve having a base portion 30 and a sleeve portion 30 a. Molded into the side walls 30 a of sleeve 30 during its manufacture are the two protrusions 50 used to impart a spiral spin to football 19 when it is launched. If no spiral spin is desired, these protrusions 50 may be eliminated.

Either fastened to base portion 30 or made as part thereof are four legs or prongs 32, only two of which are shown in this figure. All four legs are shown in FIG. 8 and in the midst of them is defined a cylindrical space with a conductive pin 31 in the middle. It is into this space that cylindrical element 28 in the end of barrel 12 slides when football 19 is mounted on end 16 of barrel 12. This is seen in and described with reference to FIG. 3. Surrounding legs 32 are two O rings 33 and 34, only one of which is seen in FIG. 8. These O rings serve two purposes as described with reference to FIG. 3.

The end 12 a of barrel 12 has a constriction shaped therein as shown. That constriction forms a cylindrical hole the diameter of which is slightly smaller than the outside diameter of O rings 33 and 34. It is this feature that contributes to creating an air tight seal at the end of barrel 12 as described hereinafter in greater detail with reference to FIG. 3.

Inside end 16 of barrel 12 is an element 27 that is connected to rod 18. Element 27 moves freely inside barrel 12 and coaxially therewith. Element 27 has formed therewith a cylindrical element 28 that has an outside diameter that will require it to be force fit between the four legs or prongs 32 with O rings 33 and 34 in cavity 21 of football 19 when football 19 is mounted on the end of barrel 12. Element 27 has holes 49 there through that permit compressed air in chamber 11 and barrel 12 to travel out of barrel 12 around element 28 to launch football 19.

There are two conductors 17 a and 17 b making up a wire cable 17 that is routed through chamber 11 and barrel 12 as seen in FIG. 1. These conductors are contained within an insulation jacket of cable 17 until they pass through a hole 49 through element 27. The individual wires 17 a and 17 b enter through the walls of cylindrical element 28 and are attached to the walls thereof as shown. These wires do not touch each other. The ends 17 a 1 and 17 b 1 of these wires are fastened to the end of element 28 as shown. The purpose of wires 17 a and 17 b, in conjunction with conductive pin 31 inside cavity 21 of football 19, is to create a safety switch 59 (FIG. 6) that prevents any items, other than the football 19 provided with apparatus 10 from being placed on the end of barrel 12 and being launched. When football 19 is mounted on the end of barrel 12 in preparation for launching, as shown in FIG. 3, conductive pin 31 in cavity 21 in the rear of football 19 enters the center area of element 28 and contacts both wires 17 a and 17 b as described in greater detail with reference to FIG. 3. This completes a circuit to activate air compressor 47 as is described in greater detail with reference to FIG. 6. This provides a first level of safety against apparatus 10 being used to launch anything other than football 19.

A second level of safety is also provided against misuse of the throwing apparatus 10. When the ball is not positioned on the end of the barrel, the chamber and barrel of the apparatus are not sealed to be able to build up air pressure if compressor 47 is energized without the use of football 19. This is because of holes 49 through element 21 and the space around element 28 to the open end 16 of barrel 12. As a result a jumper may not be placed across the mating contacts in the launching end of the barrel to activate the compressor 47 and build up air pressure in chamber 11 and barrel 12. This will be better understood when reading the description of FIG. 3.

FIG. 3 shows a side cutaway view of the launching end 16 of barrel 12 with football 19 mounted fully thereon for launching. When football 19 is placed on end 16 of barrel 12 in preparation for launching, protrusions 50 ride down grooves 15 as described with reference to FIG. 1. The outside diameter of barrel 12 is only slightly smaller than the inside diameter of wall portion 30 a inside cavity 21 of football 19 for this purpose. When football 19 is fully seated on the end of barrel 12 the end of the barrel bottoms in plastic piece 30 as shown. In reaching this position the inner walls of the enlarged end portion 12 a of barrel 12 are forced over the outside of O rings 33 and 34. This creates an air tight seal so that air being pumped in chamber 11 and barrel 12 by compressor 47 cannot escape until football 19 is to be launched. This also helps seat the inner walls of cylindrical element 28 tightly against conductive pin 31 to close the safety switch and thereby activate compressor 47. Thus, compressed air may not be built up to launch anything other than football 19 or another approved sports ball. If pressure inside barrel 12 ever exceeds safe limits and is not released via the rearward movement of rod 18 to launch football 19 the ball will be nevertheless be launched from barrel 12 by overcoming the friction and seal created by O rings 33 and 34 against the outside wall of element 28.

As will be better understood after reading the description of FIGS. 4 and 5, compressed air will launch football 19 when element 27 is moved to the left by the rearward movement of rod 18 to pull element 28 out from amongst legs or prongs 32.

FIG. 4 shows a side cutaway view of the launching end 16 of barrel 12 with football 19 fully mounted thereon just before launching when element 27 inside barrel 12 is moved to the left to break the air seal created by O rings 33 and 34 and release the compressed air in chamber 11 and barrel 12. How element 27 is moved away from football 19 will be understood after reading the description of FIG. 5 but, briefly, a piston 41 at the rear of apparatus 10 in chamber 37 that is also fastened to rod 18 pulls rod 18 to the rear and thereby pulls elements 27 and 28 toward the rear of apparatus 10. At the same time, as football 19 is launched, conductive pin 31 is no longer in contact with wires 17 a and 17 b and compressor 47 ceases functioning because the safety switch is opened.

FIG. 5 shows a side cutaway view of a spring loaded piston 41 at the rear of throwing apparatus 10 in chamber 37. Piston 41 is used to pull rod 18 rearward under the influence of the increasing air pressure inside chamber 11 and barrel 12 and thereby cause football 19 to be launched. At the rear of air chamber 11 is a chamber 37 in which air piston 41 and a spring 39 are located. Rod 18 passes through piston 18 which is attached to rod 18 at point 43 and an air tight seal is created at that point. The outside diameter of air piston 41 is a little smaller than the inside diameter of chamber 37. To create an air tight seal around piston 41 one or more O rings 42 are mounted on the periphery of piston 41 that fit snugly against the inside wall of chamber 37.

Behind air piston 41 is a spring 39. One end of spring 39 sits in a recess (not shown) in the rear of piston 41, and the other end of the spring sits in a retainer cup 40. Cup 40 moves easily in chamber 37. Rod 18 passes through a hole in the middle of cup 40 and through a screw on end cap 38. With the parts assembled as shown end cap 38 is screwed onto the end of chamber 37. Cap 38 serves as a manual adjustment to set the distance that football 19 will be propelled. It can be seen in FIG. 7 that cap 38 is not screwed down fully onto the threaded rear end of chamber 37. When cap 38 is screwed fully onto chamber 37 spring 39 is obviously compressed the most and visa versa. The more that spring 39 is compressed the greater must be the air pressure in chamber 11 before piston 41 can move far enough to the left to cause a football 19 to be launched.

When a football 19 is mounted on the end of barrel 12 and compressor 47 is energized, air from the compressor enters air chamber 11 via a pipe or tubing 35 that passes through the wall of chamber 11. An air tight seal is created between tubing 35 and the wall of chamber 11 by a sealant 36. Seal 36 prevents compressed air from escaping air chamber 11.

As air pressure increases in chamber 11 the pressure pushes against the face of air piston 41 and slowly moves it to the left, away from chamber 11. With air piston 41 attached to rod 18 and the rod is also connected to element 27 at the end of barrel 12, element 27 moves to the left a like distance. Thus, element 28 is being withdrawn from conductive pin 31 inside the base of football 19 at the same rate. Eventually piston 41 and elements 27 and 28 move to the rear far enough to allow compressed air to be released to launch football 19. The more spring 39 is compressed the higher the air pressure at launch point and the further football 10 will be thrown, and visa versa. After football 19 is launched the air pressure in air chamber 11 is zero and compressor 47 ceases functioning because the safety switch 59 has been opened as previously described. At that time spring 39 expands and returns air piston 41 to its normal position as shown in FIG. 5.

FIG. 6 shows a block schematic diagram of the circuitry used to power throwing apparatus 10. There is a football safety switch 59, which in one embodiment of the invention is located at the end of barrel 12, and is used to energize compressor 47 only if and when a football ball 19 is mounted on the end of barrel 12. In another embodiment of the invention disclosed hereinafter safety switch 59 is located near the base of the barrel 12 as shown in FIGS. 9 and 10. There is also main power switch 14 in series with football safety switch 59.

Ball throwing apparatus 10 may be powered by rechargeable battery 13 that is also shown in FIG. 1. Alternatively, apparatus 10 may be powered by a small AC to DC converter of a type known in the art and used to power many small electrical devices. To shift between the two sources of power a transfer switch 45 is provided. Switch 45 is known in the small tape recorder and other arts that use either a battery or AC/DC power converter to power the device. The power converter has a male jack on its end, and a female power receptacle (not shown) on main body 52 of apparatus 10 has the transfer switch 45 as part thereof. When the male jack is plugged into the receptacle the transfer switch 45 is operated. This opens a path to battery 13 and closes a path to converter 44 which is then used to power compressor 47. When the male jack of the power converter is withdrawn transfer switch 45 reestablishes the connection to battery 13.

When battery 13 is being utilized to power compressor 47 there is a closed circuit through battery 13, compressor 47, main power switch 14, safety switch 59, and transfer contact 45. When converter 44 is being used to power apparatus 10 and transfer switch 45 is operated there is a complete circuit through AC/DC converter 44, compressor 47, main power switch 14, safety switch 59, and transfer contact 45.

In FIG. 7 is shown a side view of a grooved football 19 used with apparatus 10. Football 19 is made of a medium rigidity, foam material. In the rear of football 19 is a cavity 21 in which are located the prongs 32 and “O” rings 33 and 34 for sealing barrel 12, and conductive pin 31 that closes safety switch 59 to only permit compressor 47 to be activated when football 19 is mounted on launching end 16 of barrel 12. It should be noted that football 19 has a number of straight grooves 20 on its outer surface. These grooves 20 do not wrap helically around the outer surface of football 19, but rather are straight and oriented at an angle to the longitudinal axis of football 19. When football 19 is launched from apparatus 10 air passing over the surface of the ball interacts with the walls of grooves 20 to maintain the spiral motion of football 19 in flight. While grooves 20 are primarily used to assist in providing or maintaining a spin to football 19 while it is in flight, they may also be used to hold the ball when manually throwing same.

In FIG. 8 is shown a rear view of football 19 for the first embodiment of the invention and showing cavity 21 in more detail. Inside cavity 21 are mounted elements that are primarily shown and described with reference to FIGS. 4 through 6. The conductive pin 31 is shown that is used as part of safety switch 59 to complete a circuit to activate compressor 47. Pin 31 must close mating contacts 17 a 1 and 17 b 1 in the launching end 16 of barrel 12 when the ball is placed on the end of the barrel to close the safety switch. The closed contact permits air compressor 47 to be activated to produce pressurized air in chamber 11 and barrel 12 for launching football 19. This provides a first level of safety against misuse of apparatus 10 to launch anything other than approved football 19 or another approved sports ball. The rear view of football 19 showing cavity 21 differs somewhat for the second embodiment of the invention and is not shown. Instead of elements 31 and 32 there are elements 67 and 68, and instead of protrusion 50 there are helical protrusions 72, all shown in FIG. 9.

Inside the cavity of football 19 for the first embodiment of the invention is a four pronged element 32 utilizing spring pressure provided by O rings, one of which 33, is shown around the four prongs of element 32. Elements 32 with O ring 33 cooperate with an element 28 inside the outer end 16 of barrel 12 to create an air tight seal that permits air pressure to build up in barrel 12 and chamber 11 when football 19 is mounted on launching end 16 of the barrel. This cooperation is best shown in and described with reference to FIG. 3.

To release the air pressure and launch a football 19 on end 16 of barrel 12 a manually adjustable release mechanism is provided that is shown and described with reference to FIGS. 2 through 5. As briefly mentioned with reference to FIG. 1, and described with reference to FIG. 5, when air pressure builds up in chamber 11 rod 18 moves to the rear of apparatus 10 and stored air pressure is released into cavity 21 to launch football 19.

Also shown inside cavity 21 in FIG. 8 is one of two protrusions 50. The two protrusions are spaced one-hundred eighty degrees around the inside wall of cylindrical cavity 21 so only one protrusion is seen in FIG. 3. These protrusions 50 are used to impart a spiral spin to football 19 as it is launched from barrel 12. In FIG. 1, on the outer surface of barrel 12, are cut two helical grooves 15 spaced one-hundred eighty degrees from each other. Accordingly, only one groove 15 shows in FIG. 1. When football 19 is placed on end 16 of barrel 12 each of the protrusions 50 rides down along one the two grooves 15. As football 19 is launched the protrusions 50 ride up along grooves 15 imparting the spiral spin to the football.

In FIGS. 9 through 11 is shown a second embodiment of the invention that differs from the first embodiment but still has the same novel features of: (a) a safety interlock that does not permit any items, other than the football provided with the throwing apparatus, from being placed on the end of the barrel and being launched, (b) a safety interlock that does not permit air pressure to be built up unless the football provided with the throwing apparatus is placed on the end of the barrel, (c) adjustable air pressure for changing the distance a football will be thrown, and (d) spiral rifling on the barrel and inside the base of the football that imparts a spiral spin to the football when it is launched.

In FIG. 9 is a side cutaway view of the second embodiment of the invention showing the launching end of a barrel 12 with a football 19 being partially slid thereon. Alike the first embodiment of the invention there is a main portion having a chamber 11 with barrel 12, an air compressor 47, a main power switch 14, and a battery pack 13 with release mechanism 12. There are also spiral rifling grooves 73 in the outer surface of barrel 12. Further, football 19 has a cylindrical cavity in its base in which is inserted and fastened a cylindrical plastic sleeve 66 that has a cylindrical portion 67 with an “O” ring 68 thereon for sealing the end of barrel 12 when football 19 is mounted on barrel 12. Sleeve 66 has spiral protrusions or ridges 72 around its inner cylindrical surface that mate with and slide easily along spiral grooves 73 around the outer surface of barrel 12 when football 19 is mounted onto the end of barrel 12. As football 19 is launched from the end of barrel 12 using air pressure these grooves 73 and ridges 72 impart a spiral spin to football 19. To help differentiate between the spiral ridges 72 and the spiral grooves 73 the ridges 72 are shown with cross bar hatching while the grooves 73 in the outer surface of barrel 12 have none. In addition, in FIGS. 9 and 10 the ridges 72 are intentionally shown interrupted and do not touch other elements of the drawing in order to eliminate any confusion. In a real side cutaway the ridges 72 would actually appear to touch element 67 and barrel 12. Although not clear in FIG. 9, a portion of ridges 72 lie within a portion of the grooves 73.

In FIG. 9 the football safety switch 48 of FIGS. 2 through 6 that is implemented on the end of barrel 12 with the first embodiment of the invention is replaced and in this second embodiment of the invention is located in the main body 52 as switch 59 with actuating arm 60. Switch 59 serves the same purpose as switch 48 in FIG. 3 and merely replaces it. When no football 19 is fully inserted onto barrel 12, as is the case in FIG. 9, actuating arm 60 is not depressed to actuate safety switch 59. Thus, compressor 47 is not actuated even though the series connected main power switch 14 is operated.

In addition, if compressor 47 is somehow wrongfully actuated and air is pumped into chamber 11 at inlet 83, no air pressure can build up in chamber 11 and barrel 12 to launch football 19 until the end of barrel 12 is sealed. The sealing of the outer end of barrel 12 can only be accomplished when an authorized football 19 is placed on the end of barrel 12, just as with the first embodiment of the invention. The sealing of the barrel and chamber is accomplished with element 67 and “O” ring 68 as is described in detail with reference to FIG. 10.

There are other elements shown in FIG. 9 that are positioned above switch 59. They provide the same functions of air pressure control and launching of football 19 as with the first embodiment of the invention. These elements are described in detail with reference to FIG. 11 which is an enlarged view of these elements in this Figure. Briefly, there is a latching latch 58 that inserts into a hole 71 in the side wall of plastic sleeve 66 inside cavity 70 of football 19 when it is fully inserted onto the end of barrel 12 until a pre-selected level of air pressure is reached, at which point locking latch 58 is retracted from hole 71 to release and launch football 19. There is also means 61 for manually adjusting the air pressure level at which football 19 will be launched.

In FIG. 10 is another side cutaway view of the second embodiment of the invention showing the launching end of barrel 12 with a football 19 fully mounted thereon and ready for launching. When football 19 is fully inserted onto the end of barrel 12 plastic sleeve 66 contacts the ramped front edge of spring loaded latching latch 58. This causes latching means 59 to be depressed downward until it is in line with hole 71 through the side wall of plastic insert 66, at which time the tip of latching latch 58 moves upward and extends into hole 71, as shown. Football 19 is thereby prevented from being launched from the end of barrel 12 until the manually set launching air pressure is reached or until a manual release button 88 is depressed. While a separate manual release button 88 is shown in FIGS. 10 and 11, it may be eliminated and a user can push down directly on the top front of trip arm 65, in the same place that button 88 contacts trip arm 65, to release football 19 as described above.

When football 19 is fully seated on the end of barrel 12 the end of the barrel is fully sealed and air pressure can build up inside chamber 11 and barrel 12. At the same time the surface of football 19 contacts and depresses actuating arm 60 and thereby operates football safety switch 59. Since switch 59 is connected in series with main power switch 14, as shown in FIG. 6, when switches 14 and 59 are both closed compressor 47 functions.

Before air pressure can build up inside chamber 11 and barrel 12 the end of the barrel must be sealed. The sealing is accomplished by a cylindrical protrusion 67 in the base of cylindrical plastic sleeve 66 and “O” ring 68 mounted thereon. The outer diameter of the “O” ring is slightly larger than the inside diameter of the reinforced end 69 of barrel 12. When football 19 is fully seated on the end of barrel 12 the “O” ring and the end of protrusion 67 on which it is mounted are forced inside the open end of barrel 12. The “O” ring is slightly compressed and creates an air seal at the end of barrel 12. More than one “O” ring may be utilized for sealing the end of barrel 12 as required.

To remove football 19 from the end of barrel 12 after it has been fully seated and locked thereon by locking latch 58 a manual release button 88 on top of the mechanism is provided. When release button 88 is depressed downward, as indicated by the arrow, button 88 presses downward on the top left surface of a trip arm 65. Trip arm 65 rotates counter clockwise around pin 74 and locking latch 58 moves downward to thereby release football 19. The manual release button 88 may also be used to launch football 19 before the football is released dependent on the setting of a manually adjustable control 61 which is described in detail with reference to FIG. 11. In an alternative embodiment of the invention there is no release button 88. Rather, the top is open and shorter than shown so a user can push down directly on the top front of trip arm 65, in the same place that button 88 contacts trip arm 65, to release football 19 as described above.

More particularly, trip arm 65 is “L” shaped and has locking latch 58 at its lower end. Trip arm 65 is mounted on and pivots about pin 74. The top of trip arm is held to the right by a spring 64 that creates a clockwise torque about pin 74. Manual release button 88 is located on the top left side of pin 74 and when it is depressed downward it creates a counter-clockwise torque about pin 74. When the counter-clockwise torque is greater than the clockwise torque trip arm 65 rotates counter-clockwise and latching latch 58 is moved downward out of hole 71 to thereby release football 19. Any air pressure built up inside chamber 11 and barrel 12 causes football 19 to be launched from the end of barrel 12. As football 19 is launched from the end of barrel 12 the protrusions 72 inside plastic piece 66 inside the base of football 19 ride along the spiral grooves 73 on the outside surface of barrel 12. This imparts the spiral spin to football 12. As previously described with reference to FIGS. 7 and 8, as air passes over grooves 20 on football 19 while it is in flight, the air movement presses on the sidewalls of grooves 20 and assists in maintaining the spiral spin of football 19.

FIG. 11 is a side cutaway view of the alternative embodiment of the invention showing in expanded detail the pressure sensing and football releasing mechanisms that are located on top of chamber 11 and barrel 12 as shown in FIGS. 9 and 10. The pressure sensing and projectile releasing mechanisms are mounted inside a housing that is sealed from chamber 11 and barrel 12, and is denoted by the heavier black lines in FIG. 11. If the elements making up the pressure sensing and projectile releasing mechanisms are not sealed from chamber 11 and barrel 12, any air being pumped into chamber 11 at inlet 83 would escape around locking latch 58 and around manual release button 88 and no pressure could build up to launch football 19.

The operation of trip arm 65 and its latching latch 58 are described above but is repeated here. Trip arm 65 is “L” shaped and has locking latch 58 at its left end. Trip arm 65 is mounted on and rotates freely about a pin 74. The top right end of trip arm 65 is connected via a stretched spring 64 to an air pressure adjustment member 62. The stretched spring 64 places a clockwise torque on arm 65 that tends to rotate it clockwise causing latching latch 58 to move upward into hole 82 through the top wall of barrel 12, but this hole is sealed from the rest of the interior of barrel 12. The trip arm 65 will rotate clockwise as far as it can.

Air pressure adjustment member 62, to which the other end of spring 64 is connected, sits in a channel 85 and can move back and forth freely in the channel as indicated by the double headed arrow. The right end of member 62 is threaded and is screwed into a mating, internally threaded cap 61 which is the manual pressure adjustment 61 that sets how far a football 19 will be launched. In FIG. 11 the internal threads of cap 61 and member 62 are shown separated only for the purpose of clarity of seeing the separate parts and how they fit together, but the threads really contact each other. Pressure adjustment cap 61 is loosely captivated between housing pieces 89 and 90 so it cannot move horizontally as it is turned. Because it is screwed onto the threaded end of member 62 it cannot move vertically. Thus, as pressure adjustment cap 61 is turned member 62 is moved to the left or right and thereby places more or less tension on spring 64. As cap 61 is turned to increase how far football 19 will be launched it causes spring 64 to be stretched further, placing a greater clockwise torque on trip arm 65. When cap 61 is turned to decrease how far football 19 will be launched it causes spring 64 to be contracted, placing a lower clockwise torque on trip arm 65.

To launch football 19 trip arm 65 must be rotated counter clockwise to lower latching latch 58 and thereby release football 19. This requires that a counter clockwise force be applied to trip arm 65. That is the function of the pressure sensing elements that are now described. There is a cylindrical channel 86 that has one end wall closed except for a small hole 84 there through via which the air pressure in chamber 11 and barrel 12 is sensed. Mounted inside channel 86 is a pressure piston 63 that can move left and right inside channel 86 as indicated by a double headed arrow. Mounted on the outside of a cylindrical portion of pressure piston 63 are “O” rings 75 that provide an air seal that prevents air under pressure inside chamber 11 from escaping around piston 63 and thereby preventing air pressure from building up inside chamber 11 and barrel 12.

The left end of pressure piston 63 is adjacent to trip arm 65 above pin 74. When air compressor 47 is started by operating the main power switch and having a projectile 19 fully inserted onto barrel 12 to operate switch 59, air pressure builds up inside chamber 11 and barrel 12. As the air pressure builds it is applied via hole 84 to the right end of pressure piston 63 thereby pushing the piston 63 to the left against trip arm 65. This occurs because the air pressure at trip arm 65 is that of the air surrounding the projectile launching mechanism. This creates a counter clockwise torque about pin 74 because piston 63 contacts arm 65 above pin 74. As the air pressure builds inside chamber 11, eventually the pressure exerted by pressure piston 63 against trip arm 65 is large enough to overcome the force created by spring 64, and trip arm 65 rotates counter clockwise enough so that its locking latch 58 moves downward to release football 19 which is then launched from barrel 12.

While what has been described herein is the preferred embodiment of the invention it will be understood by those skilled in the art that numerous changes may be made without departing from the spirit and scope of the invention. For example, there need not be a separate air chamber 11 and barrel 12. There could just be a barrel. The grooves 15 may be eliminated if it is not desired to provide a spiral spin to a sports ball such as a soccer ball. 

1. An apparatus for propelling a projectile, the apparatus comprising: a barrel for aiming in a direction that the projectile is to be propelled, the barrel having a first open end on which the projectile is mounted and from which the projectile will be propelled; a cavity in one end of the projectile that does not extend through the projectile, the cavity being placed over the first end of the barrel to mount the projectile on the first end of the barrel; means for propelling the projectile from the first end of the barrel; and means for imparting a spiral spin to the projectile as it is propelled from the barrel.
 2. The projectile propelling apparatus in accordance with claim 1 wherein the means for imparting a spiral spin to the projectile comprises: a first element on the outer surface of the barrel; and A second element inside the cavity in the one end of the projectile, the second element loosely mating with the first element on the outer surface of the barrel when the projectile is mounted on the first end of the barrel, and as the projectile is propelled from the one end of the barrel the second element rides along the first element to thereby impart a spiral spin to the projectile.
 3. The projectile propelling apparatus in accordance with claim 2 wherein the first element is a groove in the outer surface of the barrel that does not extend through the wall of the barrel and that wraps helically around the outside of the barrel and extends to the first end of the barrel, the second element is a protrusion extending from the wall of the cavity and the second element rests in the first element groove when the projectile is mounted on the first end of the barrel, and when the projectile is propelled from the first end of the barrel the second element protrusion inside the cavity in the one end of the projectile rides in the first element groove to thereby impart a spiral motion to the projectile.
 4. The projectile propelling apparatus in accordance with claim 1 wherein the projectile is a football having a generally pointed front and a rear end and the cavity is located in the rear end of the football.
 5. The projectile propelling apparatus in accordance with claim 4 wherein the projectile propelling means comprises means for providing compressed gas inside the barrel which is used to propel the projectile from the first end of the barrel.
 6. An apparatus for propelling projectiles, the apparatus comprising: a barrel for aiming in a direction that a projectile is to be propelled, the barrel having a first open end on which the projectile is mounted and from which the projectile will be propelled; means for propelling the projectile from the first end of the barrel; and means for activating the propelling means only when the projectile is mounted on the barrel; wherein the projectile has a cavity in one end that does not extend through the projectile, the cavity being placed over the first end of the barrel to mount the projectile on the first end of the barrel.
 7. The projectile propelling apparatus in accordance with claim 6 wherein the propelling means is compressed air and wherein the first end of the barrel is normally open but is sealed by a projectile mounted on the first end of the barrel so that compressed air may be stored in the barrel.
 8. The projectile propelling apparatus in accordance with claim 6 wherein the projectile has a first and a second end and comprises: first sealing means in the cavity, the first sealing means cooperating with the first end of the barrel to seal same so that compressed air may be stored in the barrel to propel the projectile.
 9. The projectile propelling apparatus in accordance with claim 8 further comprising means for adjusting the pressure of the compressed air inside the barrel at which the projectile is to be propelled from the barrel.
 10. The projectile propelling apparatus in accordance with claim 9 further comprising means for releasing the ball from the first end of the barrel when the air pressure in the barrel reaches a level at which the projectile is to be propelled from the first end of the barrel.
 11. The projectile propelling apparatus in accordance with claim 10 further comprising means for holding the projectile on the first end of the barrel, the holding means cooperating with the release means to hold the projectile on the first end of the barrel until the air pressure in the barrel reaches the air pressure at which the projectile is to be propelled from the barrel.
 12. The projectile propelling apparatus in accordance with claim 11 further comprising means for manually releasing the holding means to either manually remove the projectile from the barrel or to propel the projectile from the barrel before the release means causes the projectile to be propelled from the barrel.
 13. An apparatus for propelling footballs, the apparatus comprising: a cylindrical barrel for aiming in a direction that a football is to be propelled, the barrel having a first open end on which the football is mounted by placing a cylindrical hollow cavity in one end of the football over the first end of the barrel, and the football is propelled from the first open end of the barrel in the direction the barrel is aiming; sealing means inside the cylindrical hollow cavity in the one end of the football for sealing the first open end of the barrel when the cylindrical hollow cavity of the football is placed over the first end of the barrel; and a source of compressed air for compressing air inside the barrel to be used for propelling the football from the first open end of the barrel, the air inside the barrel being compressed only when the cylindrical hollow cavity in the one end of the football is placed over the first open end of the barrel and the barrel is sealed by the seating means; wherein the first open end of the barrel is normally open but when the football is mounted thereon the open first end of the barrel is sealed by the sealing means.
 14. (canceled)
 15. The projectile propelling apparatus in accordance with claim 13 further comprising means for adjusting the pressure of the compressed air inside the barrel at which the projectile is to be propelled from the first end of the barrel.
 16. The projectile propelling apparatus in accordance with claim 15 farther comprising means for releasing the ball from the first end of the barrel when the air pressure in the barrel reaches a level at which the projectile is to be propelled from the first end of the barrel.
 17. The projectile propelling apparatus in accordance with claim 16 further comprising means for holding the projectile on the first end of the barrel, the holding means cooperating with the release means to hold the projectile on the first end of the barrel until the air pressure in the barrel reaches the air pressure at which the projectile is to be propelled from the first end of the barrel.
 18. The projectile propelling apparatus in accordance with claim 17 further comprising means for manually releasing the holding means to either manually remove the projectile from the barrel or to propel the projectile from the first end of the barrel before the release means causes the projectile to be propelled from the first end of the barrel.
 19. The projectile propelling apparatus in accordance with claim 1 wherein the projectile comprises: an oblate spheroid body having a substantially symmetrical shape about a longitudinal axis and having an outer surface, the first end of the oblate spheroid body being on the longitudinal axis and having the cylindrical hollow cavity; a plurality of straight, parallel grooves in the outer surface of the projectile that are each at an angle with respect to the longitudinal axis of the projectile; and as the projectile travels through the air the air moving in the grooves interacts with the side walls of the grooves to cause a spiral spin to the projectile or to maintain an initial spiral spin of the projectile.
 20. The projectile in accordance with claim 19 wherein the projectile is made from an elastic foam material.
 21. The projectile in accordance with claim 20 wherein the projectile is a football. 